Stereolithography is a widely adopted technique in modern three-dimensional printing technologies. A printer utilizing stereolithography technique includes a container, a laser, a scanner, and a forming mechanism with a forming platform. A light-curable liquid is contained in the container. The laser is located at a position lower than the container and emits laser beams toward the scanner. The scanner is located underneath the container and reflects the laser beams toward a base wall of the container in order to cure the light-curable liquid. The forming platform is vertically movable relative to the base wall of the container for extending into the container and pulling the product of the cured light-curable liquid away from the container.
In order to form a product with precise shape and dimensions, it is necessary to precisely control the relative position between the forming platform and the container. Also, it is important to maintain stability of the forming platform during vertical movement relative to the container.